Answer:
Step-by-step explanation:
They are showing you how to factor 12-9i+8i-6i².
Find the greatest common factor in each row and each column.
Blue: GCF of 12 and -9i = 3
Orange: GCF of 8i and -6i² = 2i
Red: GCF of 12 an 8i = 4
Green: GCF of -9i and -6i² = 3i, but both terms are negative, so use -3i